1. Field
The presently disclosed subject matter relates to vehicle lights and headlights using a matrix type semiconductor light source, and more particularly to vehicle headlights using a matrix type semiconductor light source that can provide a favorable light distribution pattern, which includes a central portion having high brightness in a wide range of light distribution pattern.
2. Description of the Related Art
Vehicle headlights that include a plurality of LED chips as a light source to form a light distribution pattern having high brightness have been developed in recent years. The vehicle headlights can be classified into two major groups: a reflector type headlight; and a projector type headlight. A conventional LED light source using a plurality of LED chips and a vehicle headlight using the light source, for example, are disclosed in Patent Document No. 1 (co-owned U.S. Pat. No. 7,520,647). The conventional LED light source disclosed in Patent Document No. 1 can be used as a light source for a reflector type headlight.
When the conventional LED light source is used for a vehicle headlight, the headlight may form a predetermined light distribution pattern by reflecting light emitted from the LED light source by a reflector. When a light distribution pattern for a low beam is formed by the LED light source and the reflector, the vehicle headlight may form a light distribution pattern for a low beam including a horizontal cut-off line by using a shade to shield an upward light that gives a glaring type light to an oncoming vehicle and the like.
On the other hand, a conventional vehicle headlight using a plurality of LEDs that can be used as a light source for a projector type headlight is disclosed in Patent Document No. 2 (Japanese Patent Application Laid Open JP2008-513967). FIG. 6a is a schematic side view showing the conventional vehicle headlight disclosed in Patent Document No. 2, and FIG. 6b is a close-up top view showing a light source array 51 of the vehicle headlight of FIG. 6a. 
The conventional vehicle headlight includes: a plurality of LEDs; light source array 51 composed of a plurality of optical fibers and guiding light emitted from the LEDs; and a projector lens 50 projecting the light emitted from the LEDs and guided by the light source array 51. The light source array 51 includes a first light source array 51a forming a light distribution pattern for a low beam and a second light source array 51b forming a light distribution pattern for a high beam along with the first light source array 51a. 
When the conventional vehicle headlight forms a light distribution pattern for a low beam, light projected by the first light source array 51a flips via the projector lens 50 and may be emitted in a light-emitting direction of the vehicle headlight as the light distribution pattern for a low beam. When the vehicle headlight forms a light distribution pattern for a high beam, light projected by the first and the second light source arrays 51a and 51b flips via the projector lens 50 and may be emitted in the light-emitting direction of the vehicle headlight as the light distribution pattern for a high beam including an upward light, which is projected by the second light source array 51b. 
Accordingly, this conventional headlight may form light distribution patterns for a low beam and a high beam without a reflector or shade, which are provided in the conventional reflector type headlight. In this case, a density of a central portion of the light source array 51 may become high and a density of right and left sides may become low, so that central portions of the light distribution patterns for a low beam and a high beam can include brighter regions as compared to the right and left sides.
However, because the light distribution patterns for a low beam and a high beam may be reflected directly by the light-emitting location of the optical fibers and the light intensity distribution of the light source array 51, dark portions may occur between the adjacent optical fibers located near the right and left sides of the light source array 51 and therefore, may cause dark portions on the light distribution patterns. Thus, it may be difficult for the conventional headlight to form a smooth light distribution pattern. In addition, it may be difficult for the conventional headlight to form a wide range of light distribution pattern due to use of the projector lens 50.
Moreover, when each of the optical fibers of the light source array 51 is coupled with each of the plurality of LEDs, the number of LEDs and the number of couplers between the optical fibers and the plurality of LEDs may not only increase, but a light distributing structure for the light source array 51 may also become large. When some of the optical fibers of the light source array 51 are coupled with each of the plurality of LEDs, the light distributing structure for the light source array 51 may become complex although the number of LEDs may diminish. Furthermore, a rugged high quality clamping device for use with the light source array 51 may be required for preventing the optical fibers from vibrating. Thus, use of the light source array 51 including the optical fibers may result in a high cost conventional headlight.
The above-referenced Patent Documents are listed below, and are hereby incorporated with their English abstracts in their entireties.    1. Patent Document No. 1: U.S. Pat. No. 7,520,647.    2. Patent Document No. 2: Japanese Patent Application Laid Open JP2008-513967 (WO2006/034329).
The disclosed subject matter has been devised to consider the above and other problems, features, and characteristics. Thus, embodiments of the disclosed subject matter can include vehicle lights, and headlights that can form a favorable light distribution pattern for a high beam, which includes a central portion having high brightness in a wide range of smooth light distribution pattern and without the need for optical fibers. The disclosed subject matter can also include a reflector type headlight using a matrix type semiconductor light source that can form a favorable light distribution pattern for a low beam having a wide light-emitting area and a brighter central portion without the use of a shade and/or optical fibers.